The lateral fissure has now been extensively exposed from above by the removal of the frontal and parietal opercula. The superior longitudinal fasciculus (4) has been cut away to reveal the insula. The principal cortical branches of the middle cerebral artery lie within the lateral fissure. The portion of the temporal lobe facing the fissure displays transversely oriented gyri (of Heschl) wherein the fibers of the central auditory pathway terminate.

1
.

Medullary substance of superior frontal gyrus

2
.

Superior cerebral vein is in superior frontal sulcus

3
.

Cingulum (cut off)

4
.

Anterior continuation of superior longitudinal fasciculus

5
.

Frontal branches of orbitofrontal artery

6
.

Insula

7
.

Artery of precentral sulcus

8
.

Artery of central sulcus (Note cut end of great anastomotic vein in meninges close to cut end of this artery)

9
.

Transverse temporal gyrus (of Heschl)

10
.

Sulcus circularis Note: this sulcus surrounds the insula in the depths of the lateral fissure